ClockworkMod – also known as Clockwork and CWM – is a custom recovery for Android phones and tablets that allows you to perform several advanced recoveries, restoration, installation and maintenance operations on your Android device that are not possible with the stock recovery. This guide will cover all that this recovery is capable of doing, and how to do it.

Here is what shall be covered in this guide:

Now let’s take a look at each of these topics in detail.

All Android devices are shipped with a recovery console that is basically a partition on the device’s internal memory and can be booted into. The stock recovery of almost all Android devices provides a few basic yet handy options that allow you to factory reset your device and also to recover its operating system using an official ROM in zip format, but that is all you can do with it. That’s where a custom recovery comes handy…

A custom Android recovery basically replaces the stock recovery with one that lets you do all you can do with the stock recovery, plus a plethora of more options to give you a lot more control on your device. With a custom recovery, you can install official and unofficial ROMs as well as other updates including apps, themes, kernels etc. using zip files, wipe not just user data but pretty much every partition on your device, mount the storage card for USB mass storage access without leaving recovery, partition your SD card, wipe Dalvik cache and battery stats, fix permissions, perform, manage and restore backups and so on.

ClockworkMod recovery is one of the most widely used custom Android recoveries that is available for most mainstream Android devices. This recovery has been developed by Koushik Dutta (also known as Koush) – the creator of Android ROM Manager.

What sets ClockworkMod recovery apart from most other custom Android recoveries is its dead-simple installation process on most devices. It does require you to fully root your device in order to be installed but once rooted, installing it is as simple as installing ROM Manager and choosing the proper option.

However, in certain cases, this ROM Manager method will not work. That is the case for MediaTek chipset based devices and here is a warning for any owner of such a device: don’t use ROM Manager or else you’ll get a brick!!!

For those, the method you should follow in order to install ClockworkMod recovery is described in both my MT65x3 and MT6516 flashing tutorials:

• MT65x3 flashing tutorial
• MT6516 flashing tutorial (instructions for flashing recovery are right in the end of the tutorial)

Please note that those are just generic flashing tutorials. You need to find the ClockworkMod recovery image specifically designed for your device.

Once you have ClockworkMod recovery installed on your Android device, booting into it is quite simple:

• Using the extended power menu on your Android device:

This is another way of booting into recovery, but please note that the extended power menu is only present on some custom ROMs.

 

Feature Tour

Let’s now take a look at all the options CWM recovery offers you to manage your Android device. In this example, the phone used was my G11i Pro running ClockworkMod recovery 5.0.2.8 but the details should apply to other devices and other 3+ versions of the recovery as well.

This is what you see when you reboot your device into ClockworkMod recovery:

You can navigate these options by using the ‘Volume-Up’ and ‘Volume-Down’ keys to highlight an option and the ‘Power’ key to enter/launch the highlighted option on most Android devices. On devices equipped with a trackball or an optical trackpad such as G1, G2, Nexus One, HTC Desire, etc., the trackball or trackpad can be used for navigation and clicking it can be used to enter/launch the selected option. Let’s review each of these options and their sub-menu options in detail.

1 – reboot system now

This one is self-explanatory.

3 – wipe data/factory reset

This option wipes all user data on the device as well as cache. Doing this will leave your phone in the state it was in when you bought it or when any custom ROM was first installed. It will also wipe any sd-ext partition that you might have setup (more on this later).

4 – wipe cache partition

Wipes the cache partition of the device to clear all the data accumulated there overuse. This is often used before installing a new ROM, app, kernel or any similar mod via recovery.

5 – install zip from sd card

This option brings up the following sub-menu:

5.1 – apply /sdcard/update.zip

1. This one is essentially the same as the

apply update from sdcard

option of the main menu.

5.2 – choose zip from sdcard

Lets you install any zip file (with any name) from any location on your SD card. The file can be for a ROM, a kernel, an application, a theme or any mod as long as it is in recovery-flashable zip format. This is the most widely used option for installing a ROM that you have downloaded and copied to your SD card. Entering this option will bring up a screen that will allow you to browse your SD card for the zip file and select it for installation as in this screenshot:

5.3 – toggle signature verification

Turns the signature verification on and off. When signature verification is on, you will not be able to install any custom ROMs that haven’t been signed by the developers (most custom ROMs aren’t signed). Switching it off skips the signature verification check and proceeds with the installation.

5.4 – toggle script asserts

Seldom-used option for a vast majority of users. It simply turns script asserts on or off. If you don’t know about these, it’s best not to change this option.

5.5 – +++++Go Back+++++

Takes you back to the main recovery menu, obviously!

6 – backup and restore

This is without any doubt one of the most important features provided by a custom recovery, the backup and restore feature – also known as Nandroid backup – allows you to take a snapshot of your phone’s entire internal memory including all partitions, and save it on the SD card. Here is how it looks:

6.1 – Backup

Takes a Nandroid backup, as explained above.

6.2 – Restore

Lets you restore a previously taken backup. Entering this option presents you with a list of existing backups from the SD card that you can choose from for restoration.

6.3 – Advanced Restore

1. This option is similar to the

Restore

option but once a backup has been selected to be restored, this option allows you to choose what parts of it to restore. You can choose to restore the boot, system, data, cache and sd-ext partitions, as shown here:

7 – mounts and storage

Allows you to perform maintenance tasks on all the internal and external partitions of your android device:

7.1 – mount/unmount /system, /data, /cache, /sdcard or /sd-ext

These options let you toggle between mounting or unmounting these respective partitions. Most users don’t need to change these options.

7.2 – format boot, system, data, cache, sdcard or sd-ext

These let you directly format any of these partitions. Take extreme care with this option as formatting any of these partitions will result in losing all data on them, especially the boot and system partitions. Formatting the system partition will remove your ROM and leave your phone without an operating system while wiping the boot partition may brick your phone unless you restore or flash another one before rebooting your device. To learn more about the contents of all these partitions, see our guide to Android partitions.

7.3 – mount USB storage

Lets you enable USB mass storage mode for your SD card right from recovery so that you can connect it to your computer via USB and transfer any files to/from it without having to leave recovery.

8 – advanced

This section contains a few options most users will not require, though these can come handy quite often, especially wiping Dalvik cache, which is required before most ROM installations. Here are the options from this section:

8.1 – Reboot Recovery

Lets you directly and very conveniently reboot from recovery right back into recovery. This is useful option for certain back-to-back installations that require the device to at least boot once between them.

8.2 – Wipe Dalvik Cache

Allows you to wipe the cache for the Dalvik virtual machine (the custom-built Java virtual machine for Android).This is required before most ROM installations and at other occasions too, for fixing some problems.

8.3 – Wipe Battery Stats

Wipes the saved battery usage statistics and effectively recalibrates the battery. Useful in various scenarios when Android is not showing correct battery levels.

8.4 – Report Error

In case of errors, this feature can be used to save a log of recent ClockworkMod recovery operations on the SD card that you can later report from Android using ROM Manager.

8.5 – Key Test

Lets you press any of the hardware keys to see if they are properly functioning, and to see their key codes.

8.6 – Partition SD Card

1. This option gives you a no-frills way to partition your SD card properly for use with ROMs that support data2ext (a very handy hack for low internal memory devices that enables an /sd-ext partition on the SD card to be used as the internal user data storage i.e. as the /data partition). Once this option is selected, you will be given options to choose the sizes for the /sd-ext partition as well as an optional /swap partition on the SD card, and will then automatically format it for you, leaving the remaining space for normal SD card usage.

This option will wipe all data from your SD card so use it with caution!

 

 

 

 

 

8.7 – Fix Permissions

Fixes the file permissions for the internal memory partitions back to default. This is very useful as a fix for several errors and Force-Closes that start appearing after you or an application you installed and provided root access end up messing up the permissions of important files.

 

9 – power off

Do I need to tell you what it does?

Well… that’s all you need to know about ClockworkMod recovery.